Seawall is an important barrier of Zhejiang coastal strip. To effectively manage the information of maritime work in Zhejiang and convert the traditional management into the modern management, the information management system of maritime work based on GIS is developed. Take Kaomen seawall for example, the overall structure of information management system based on GIS is designed, focusing on the data entry, spatial attribute show, spatial attribute query, spatial information statistics and analysis. This design plays a significant role in the flood control and disaster reduction in the future, making the information management of maritime work convenient and practical.